Location: Plant Polymer ResearchTitle: Corrosion protection of steel by thin coatings of starch-oil dry lubricants Author
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 1/1/2016
Publication Date: 5/2/2016
Citation: Finkenstadt, V.L., Kenar, J.A., Fanta, G.F. 2016. Corrosion protection of steel by thin coatings of starch-oil dry lubricants. In: Sharma, B.K., Biresaw, G., editors. Environmentally Friendly and Biobased Lubricants. Boca Raton, FL: CRC Press. p. 407-417.
Interpretive Summary: Corrosion is a global problem that affects safety and economics. Products from agriculturally important crops (corn and soybean) were utilized as anticorrosive lubricants for low carbon stainless steel. Electrochemical analysis showed that thin coatings prevented corrosion on steel for an extended period of time. The starch-soybean oil coatings were manufactured and applied using current industrial technology. As a dry lubricant, this coating may help prevent corrosion during metal working. Corrosion prevention is a multi-billion dollar industry and has significant environmental impact. Starch and soybean oil are abundant, relatively inexpensive, and renewable agricultural commodities in the United States.
Technical Abstract: Corrosion of materials is one of the most serious and challenging problems faced 3 worldwide by industry. This research investigated the inhibition of corrosive behavior a 4 dry lubricant formulation consisting of jet-cooked corn starch and soybean oil on SAE 5 1010 steel. Electrochemical Impedance Spectroscopy (EIS) was used to evaluate the 6 corrosion inhibition of starch-soybean oil coatings containing varying amounts (0, 11.6, 7 26.8 and 53.4 % w/w) of soybean oil loading at 0.6 and 2.0 mg/cm2 surface coverage. At 8 high SBO loadings, coatings with higher surface coverage exhibited oil separation from 9 the dried starch film. EIS of control starch samples (0% soybean oil) indicated minor 10 protection up to approximately twice that of bare steel. The coatings were highly variable 11 in coating integrity and some phase separation occurred at higher oil loadings thus no 12 linear correlation for oil loading or surface coverage was noted. The coating comprised of 13 26.8 wt% soybean oil applied at 0.5 mg/cm2 showed maximum protection from corrosion 14 (approximately 10x that of bare steel).